Dr Bo Cao at the University of Texas said, "Our study is one of the first to locate possible damage of bipolar disorder in specific subfields within the hippocampus. This is something that researchers have been trying to answer."

Cao hopes the study, which was published in Molecular Psychiatry, will pioneer future research on details within the hippocampus as a marker for precise diagnosis and positive treatment response of bipolar.

Many people have suffered a 'nervous stomach' at times of stress and now there's robust scientific evidence to support the link between our gut and our mood.

Not only did the number of microorganisms decrease as stress became more chronic, behavioural changes suggested that the rats also began experiencing loss of pleasure and despair-like behaviour. Moreover, when these microorganisms were transferred to a new group of animals that had not been stressed, Dr. Emily Jutkiewicz found that these new animals also began to demonstrate these same behavioural changes after 5 days. This suggests a potential causal mechanism.

To test if these changes could be reproduced with human subjects, a series of human studies were carried out and this demonstrated similar reductions in microorganisms in participants suffering from both major depression and bipolar disorder. These changes were associated with increased anxiety and sleep problems and with increased complaints of general health problems.

Referring to these associations in bipolar subjects, Dr. Simon Evans concluded, "The data support the hypothesis that targeting the microbiome [microorganisms in a particular environment] may be an effective treatment paradigm for bipolar disorder."

This work is being progressed by Dr. Stephanie Flowers who has been investigating the weight gain which often accompanies atypical antipsychotic (AAP) medication. She has demonstrated how female patients with bipolar who gained weight with AAP treatment had a greater reduction in microbiome diversity than those who didn't experience weight gain.

The finding suggests that the health of our gut may also put us at increased risk for certain medication side effects, which may be yet another reason to encourage us to improve our diets.

Ketamine could be the answer for some

A review of the last ten years of research on ketamine has demonstrated that it causes a statistically significant improvement in bipolar depression over placebo.

Sarah Grady and her colleagues in the US examined seven randomised, controlled trials of ketamine usage, finding that it was also beneficial for patients with major depressive disorder. They conclude that ketamine shows promise in quickly reducing symptoms in patients with treatment-resistant depression and bipolar depression, so it may be helpful for those who have exhausted other treatment options.

For those of us who are pet loves: A charming paper on the role pets play in preserving and enhancing mental wellbeing

A qualitative study by Brooks and colleagues was conducted with people in Manchester and Southampton and concluded that the role of pets in some people's lives has been understated. See here for a fuller account.

The authors concluded that more attention should be given to encouraging pet ownership in care plans and in discussions with healthcare providers as pets could be viewed as a key source of support in managing people's mental health.